Catalytic dehydrogenation of cyclooctane in homogeneous solution with titanium, zirconium and hafnium complexes containing N,O-chelating ligands

A series of new titanium, zirconium and hafnium complexes with the heteroatom chelating ligands hydroxyquinolines, hydroxypyridines and hydroxyimines were synthesized. The complexes were activated with MAO and successfully tested for the catalytic CH activation reactions of cyclooctane. They gave TONs of 1.7–18.7 (300 °C, 16 h) in homogeneous solution. The TONs were clearly influenced by the ligand structure. The endothermic CH activation reaction with group 4 metal catalysts is preferably carried out at higher reaction temperatures (300–400 °C).

Graphical abstractA series of new titanium, zirconium and hafnium complexes with the heteroatom chelating ligands hydroxyquinolines, hydroxypyridines and hydroxyimines were synthesized and successfully tested for the catalytic CH activation reactions of cyclooctane.Figure optionsDownload full-size imageDownload as PowerPoint slide